CN114375355A

CN114375355A - Non-solvent 2K polyurethane artificial leather composition, artificial leather prepared from same and preparation method of artificial leather

Info

Publication number: CN114375355A
Application number: CN201980100243.3A
Authority: CN
Inventors: 张朝; 冯艳丽; 秦世浩
Original assignee: Dow Global Technologies LLC
Current assignee: Dow Global Technologies LLC
Priority date: 2019-09-25
Filing date: 2019-09-25
Publication date: 2022-04-19
Also published as: WO2021056229A1; JP2023500773A; JP7477598B2; US20220259798A1; EP4034703A4; EP4034703A1

Abstract

A non-solvent two-component polyurethane artificial leather composition is provided. A polyurethane composition comprises (a) a polyurethane prepolymer component comprising one or more polyurethane prepolymers prepared by reacting at least one polyisocyanate compound with at least one first polyol, wherein the polyurethane prepolymers comprise at least two free isocyanate groups; and (B) a polyol component comprising at least one second polyol; wherein the polyol component further comprises an encapsulated blowing agent comprising at least one foam core phase encapsulated within the shell. Polyurethane leather products derived from the polyurethane compositions exhibit enhanced stability, mild bubble generation, and improved cost effectiveness. Also provided are a polyurethane leather product prepared from the composition and a method for preparing the same.

Description

Non-solvent 2K polyurethane artificial leather composition, artificial leather prepared from same and preparation method of artificial leather

Technical Field

The present disclosure relates to a non-solvent two-component (2K) polyurethane artificial leather composition, an artificial polyurethane leather product prepared by using the same, and a method for preparing the artificial polyurethane leather product. The artificial polyurethane leather product exhibits enhanced stability, mild bubble generation and improved cost effectiveness.

Background

Currently, most Polyurethane (PU) artificial leathers are prepared using volatile organic solvents such as Dimethylformamide (DMF), Methyl Ethyl Ketone (MEK) and toluene. These solvent-based systems pose environmental problems due to evaporation of organic solvents during the manufacturing process and the presence of residual organic solvents in leather products, and thus the demand for environmentally friendly PU leather products is increasing. Recently, the environment-friendly PU artificial leather technology is growing very rapidly under government push and end user (brand owner) pull. Attempts have been made to minimize the use of volatile organic solvents in the manufacture of PU artificial leather. There are several new ECO-friendly (ECO) technologies in this market, such as 2K (two-component) non-solvent PU foam technology, PUD (polyurethane dispersion) foam technology and TPU foam technology. 2K non-solvent PU foams are one of the most popular technologies due to their advantages such as cost effectiveness and formulation flexibility. Foaming refers to a step of generating bubbles in a PU leather film, and is of considerable importance in artificial leather applications for achieving advantages such as lower cost, better hand, improved embossing, enhanced gas migration, etc. The conventional foaming technique for producing 2K non-solvent PU leathers is known as "moisture foaming", i.e. reacting isocyanates with water or water vapor to generate CO for foaming and frothing PU leathers₂. However, the moisture foaming technique has some disadvantages. Firstly, the mechanism of this foaming technique relies mainly on the reaction of water with isocyanates, where the isocyanates, also the raw materials for the preparation of the polyurethane, will be consumed, thus increasingThe manufacturing cost is reduced. Second, additional additives must be incorporated into the polyurethane system to stabilize the bubbles thus formed, which also increases manufacturing costs. Third, it is difficult to control the reaction between water and isocyanate, thus increasing the complexity of manufacture and routine maintenance. For the reasons mentioned above, there is still a need in the polyurethane manufacturing industry to develop a polyurethane composition that can improve the above-mentioned performance characteristics thereof in an economical manner.

After continuing their research, the inventors have surprisingly developed a polyurethane composition that can achieve one or more of the above-mentioned objectives. In particular, it was found that when the sealed foaming agent was used to manufacture a 2K non-solvent PU artificial leather product, isocyanate raw material was not wasted for foaming, a surfactant was not required to stabilize bubbles, the formation of polyurethane chains was not affected by the foaming step, and the resulting PU leather product exhibited better hand.

Disclosure of Invention

The present disclosure provides unique non-solvent two-component polyurethane artificial leather compositions, artificial polyurethane leather products prepared by using the compositions, and methods for preparing the artificial polyurethane leather products.

In a first aspect of the present disclosure, the present disclosure provides a non-solvent two-component polyurethane artificial leather composition comprising (a) a polyurethane prepolymer component comprising one or more polyurethane prepolymers prepared by reacting at least one polyisocyanate compound with at least one first polyol, wherein the polyurethane prepolymers comprise at least two free isocyanate groups; and (B) a polyol component comprising at least one second polyol; wherein the polyol component further comprises an encapsulated blowing agent comprising at least one foam core phase encapsulated within the shell.

In a second aspect of the present disclosure, the present disclosure provides a method of preparing an artificial polyurethane leather product by using the composition of the present disclosure, comprising the steps of i) reacting a polyisocyanate compound with a first polyol to form a polyurethane prepolymer component (a) comprising one or more polyurethane prepolymers, wherein the polyurethane prepolymers have at least two free isocyanate end groups; ii) mixing the polyurethane prepolymer component (a) with the polyol component (B) to form a precursor mixture; iii) applying the precursor mixture to one surface of a release film to form a green layer; iv) optionally applying a carrier layer to a surface of the green layer opposite the release film; iv) heating the green layer to form a foamed polyurethane leather layer; and v) optionally, peeling the foamed polyurethane leather layer from the release film.

In a third aspect of the present disclosure, the present disclosure provides an artificial polyurethane leather product prepared by the above method, wherein the product comprises a foamed polyurethane leather layer, an optional release film, and an optional carrier layer.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed.

Drawings

FIG. 1 is a schematic illustration of an exemplary encapsulated blowing agent;

FIG. 2 is a schematic illustration of a process for making an artificial leather article as described herein;

fig. 3a to 3e show Scanning Electron Microscopes (SEM) of the cross section and surface of PU foam manufactured in inventive examples and comparative examples of the present disclosure.

Detailed Description

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Moreover, all publications, patent applications, patents, and other references mentioned herein are incorporated by reference.

As disclosed herein, the term "composition", "formulation" or "mixture" refers to a physical blend of different components obtained by simply mixing the different components via physical means.

As disclosed herein, "and/or" means "and, or as an alternative. Unless otherwise indicated, all ranges are inclusive of the endpoints. All percentages and ratios are by weight and all molecular weights are number average molecular weights unless otherwise indicated.

In the context of the present disclosure, the term "two-component (2K) polyurethane artificial leather composition" refers to a composition comprising two components that can react with each other to produce a polyurethane artificial leather. According to embodiments of the present disclosure, the polyurethane composition is a "two-part", or "two-pack" composition comprising a polyurethane prepolymer component (a) and a polyol component (B), wherein the polyurethane prepolymer component (a) comprises at least one polyurethane prepolymer having at least two free isocyanate end groups. The polyurethane prepolymer component (a) and the polyol component (B) are shipped and stored separately and combined shortly or immediately prior to application during the manufacture of polyurethane products such as artificial leathers. Once combined, the isocyanate groups in component (a) react with the hydroxyl groups and any additional isocyanate-reactive groups (if any) in component (B), such as amine groups, thiol groups, carboxyl groups, etc., to form a polyurethane. Without being bound by any particular theory, it is believed that the incorporation of at least one encapsulated blowing agent in the preparation system can effectively improve the foaming procedure, thereby improving the performance characteristics of the resulting polyurethane foam in a cost-effective manner.

Polyurethane prepolymer component (A)A)

According to a preferred embodiment of the present disclosure, the polyurethane prepolymer is prepared by reacting an excess of monomeric polyisocyanate with a monomeric or polymeric polyol.

In various embodiments, the polyisocyanate compound used to prepare the polyurethane prepolymer is an aliphatic, cycloaliphatic, aromatic, or heteroaryl compound having at least two isocyanate groups. In a preferred embodiment, the polyisocyanate compound may be selected from the group consisting of: c comprising at least two isocyanate groups₄-C₁₂Aliphatic polyisocyanates, C comprising at least two isocyanate groups₆-C₁₅Cycloaliphatic or aromatic polyisocyanates, C comprising at least two isocyanate groups₇-C₁₅Araliphatic polyisocyanates and combinations thereof. In another preferred embodiment, suitable polyisocyanuratesThe acid ester compound comprises m-phenylene diisocyanate, 2, 4-toluene diisocyanate and/or 2, 6-Toluene Diisocyanate (TDI), various isomers of diphenylmethane diisocyanate (MDI), carbodiimide modified MDI products, hexamethylene-1, 6-diisocyanate, tetramethylene-1, 4-diisocyanate, cyclohexane-1, 4-diisocyanate, hexahydrotoluene diisocyanate, hydrogenated MDI, naphthyl-1, 5-diisocyanate, isophorone diisocyanate (IPDI), or mixtures thereof. In general, the amount of the polyisocyanate compound may vary based on the actual needs of the polyurethane foam and the polyurethane artificial leather. For example, as one illustrative example, the polyisocyanate compound may be present in an amount of 15 to 60 wt%, or 20 to 50 wt%, or 23 to 40 wt%, or 25 to 38 wt%, based on the total weight of the polyurethane composition.

According to one embodiment of the present disclosure, the first polyol used to prepare the polyurethane prepolymer may be selected from the group consisting of: c comprising at least two hydroxyl groups₂-C₁₆Aliphatic polyhydroxy alcohols, C containing at least two hydroxyl groups₆-C₁₅Alicyclic or aromatic polyhydric alcohols, C containing at least two hydroxyl groups₇-C₁₅Araliphatic polyhydroxy alcohols, polyester polyols having a molecular weight of from 100 to 5,000 and an average hydroxyl functionality of from 1.5 to 5.0, poly (C) having a molecular weight of from 100 to 5,000₂-C₁₀) Alkylene glycol or poly (C)₂-C₁₀) Polyether polyol of a copolymer of alkylene glycol, polycarbonate diol having a molecular weight of 100 to 5,000, C comprising at least two amino groups₂To C₁₀Polyamines, C comprising at least two thiol groups₂To C₁₀Polythiol, C comprising at least one hydroxyl group and at least one amino group₂-C₁₀Alkanolamines, and combinations thereof. According to a preferred embodiment, the first polyol is a polyether polyol. In various embodiments, the polyether polyol used as the first polyol has a molecular weight of 100 to 5,000g/mol, and may have a molecular weight within a numerical range obtained by combining any two of the following endpoints: 120. 150, 180, 200, 250, 300, 350, 400, 450, 500, 550, 600,700. 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200, 2300, 2400, 2500, 2600, 2700, 2800, 2900, 3000, 3100, 3200, 3300, 3400, 3500, 3600, 3700, 3800, 3900, 4000, 4100, 4200, 4300, 4400, 4500, 4600, 4700, 4800, 4900 and 5000 g/mol. In various embodiments, the polyether polyol used as the first polyol has an average hydroxyl functionality of 1.5 to 5.0, and may have an average hydroxyl functionality within a numerical range obtained by combining any two of the following endpoints: 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9 and 5.0. According to a preferred embodiment of the present disclosure, the polyether polyol is selected from the group consisting of: polyethylene glycol, polypropylene glycol, polybutylene glycol, poly (2-methyl-1, 3-propanediol), and any copolymer thereof, such as poly (ethylene oxide-propylene oxide) glycol. According to another preferred embodiment of the present disclosure, the polyether polyol may comprise at least one poly (C)₂-C₁₀) The alkylene glycol or copolymer thereof, for example, the polyether polyol may be selected from the group consisting of: polyethylene, (methoxy) polyethylene glycol (MPEG), polyethylene glycol (PEG), poly (propylene glycol), polytetramethylene glycol, poly (2-methyl-1, 3-propanediol) or copolymers of ethylene oxide and propylene oxide with primary or secondary hydroxyl end groups (polyethylene glycol-propylene glycol).

According to an embodiment of the present disclosure, polyether polyols may be prepared by polymerizing one or more linear or cyclic alkylene oxides selected from the group consisting of Propylene Oxide (PO), Ethylene Oxide (EO), butylene oxide, tetrahydrofuran, 2-methyl-1, 3-propanediol, and mixtures thereof, with a suitable starter molecule in the presence of a catalyst. Typical starter molecules comprise compounds having at least 1, preferably 1.5 to 3.0 hydroxyl groups or one or more primary amine groups in the molecule. Suitable starter molecules having at least 1 and preferably 1.5 to 3.0 hydroxyl groups in the molecule are for example selected from the group comprising: ethylene glycol, 1, 2-propanediol, 1, 3-propanediol, 1, 2-butanediol, 1, 3-butanediol, 1, 4-butenediol, 1, 4-butynediol, 1, 5-pentanediol, neopentyl glycol, 1, 4-bis (hydroxymethyl) -cyclohexane, 1, 2-bis (hydroxymethyl) cyclohexane, 1, 3-bis (hydroxymethyl) -cyclohexane, 2-methylpropane-1, 3-diol, methylpentanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, dibutylene glycol, polybutylene glycol, trimethylolpropane, glycerol, pentaerythritol, castor oil, sugar compounds, such as glucose, sorbitol, mannitol and sucrose, polyhydric phenols, resols, such as oligomeric condensation products of phenol and formaldehyde and phenol, Mannich condensates of formaldehyde and dialkanolamines (Mannich condenstates) and melamine. The starting molecule having one or more primary amine groups in the molecule may be selected from the group consisting of: such as aniline, EDA, TDA, MDA and PMDA, more preferably selected from the group comprising TDA and PMDA, most preferably TDA. When TDA is used, all isomers may be used individually or in any desired mixture. For example, 2,4-TDA, 2,6-TDA, mixtures of 2,4-TDA and 2,6-TDA, 2,3-TDA, 3,4-TDA and 2,3-TDA, and mixtures of all of the above isomers may be used. The catalyst used for the preparation of the polyether polyol may comprise a basic catalyst for anionic polymerization, such as potassium hydroxide, or a Lewis acid catalyst for cationic polymerization (such as boron trifluoride). Suitable polymerization catalysts may include potassium hydroxide, cesium hydroxide, boron trifluoride, or a double cyanide complex (DMC) catalyst, such as zinc hexacyanocobaltate or quaternary phosphazenium compounds. In a preferred embodiment of the present disclosure, the starting material polyether polyol comprises polyethylene, (methoxy) polyethylene glycol (MPEG), polyethylene glycol (PEG), poly (propylene glycol), polytetramethylene glycol, poly (2-methyl-1, 3-propane diol), or a copolymer of ethylene oxide and propylene oxide with primary or secondary hydroxyl end capping groups (polyethylene glycol-propylene glycol).

According to a preferred embodiment, the first polyol comprises only one or more polyether polyols as described above. According to a preferred embodiment, the first polyol further comprises one or more polyols other than polyether polyols as described above.

According to a preferred embodiment of the present disclosure, the amount of polyisocyanate compound is suitably selected such that the isocyanate groups are present in a stoichiometric molar amount relative to the total molar amount of hydroxyl groups included in the first polyol, the second polyol and any additional additives or modifiers. According to embodiments of the present disclosure, the polyurethane prepolymer has an NCO content of 2 to 50 wt%, preferably 6 to 49 wt%, preferably 8 to 25 wt%, preferably 10 to 20 wt%, more preferably 11 to 15 wt%, most preferably 12 to 13 wt%. According to embodiments of the present disclosure, the polyurethane prepolymer has a viscosity (average kinematic viscosity) of 50cSt to 10,000cSt, or 100cSt to 9,000cSt, or 300cSt to 8,500cSt, or 500cSt to 8,000cSt, or 500cSt to 5,000cSt, or 1,000cSt to 7,000cSt, or 2,000cSt to 6,000cSt, or 3,000cSt to 5,000cSt, or 500cSt to 5,000 cSt.

According to a preferred embodiment of the present disclosure, component (a) comprises only one polyurethane prepolymer. According to another preferred embodiment of the present disclosure, component (a) is a blend of two or more polyurethane prepolymers that differ from each other in the kind and relative content of the formulation, such as polyisocyanate and first polyol.

The reaction between the polyisocyanate compound and the first polyol may occur in the presence of one or more catalysts that can promote the reaction between isocyanate groups and hydroxyl groups. Without being limited by theory, the catalyst may comprise, for example, a glycinate salt; a tertiary amine; tertiary phosphines, such as trialkylphosphines and dialkylbenzylphosphines (dialkylbenzylphosphines); a morpholine derivative; a piperazine derivative; chelates of various metals such As those obtainable from acetylacetone, benzoylacetone, trifluoroacetylacetone, ethyl acetoacetate, etc. and metals such As Be, Mg, Zn, Cd, Pd, Ti, Zr, Sn, As, Bi, Cr, Mo, Mn, Fe, Co and Ni; acidic metal salts of strong acids, such as ferric chloride and stannic chloride; salts of organic acids with various metals such as alkali metals, alkaline earth metals, Al, Sn, Pb, Mn, Co, Ni, Cu, etc.; organotin compounds, such as tin (II) salts of organic carboxylic acids, for example tin (II) diacetate, tin (II) dioctoate, tin (II) diethylhexanoate and tin (II) dilaurate, and dialkyltin (IV) salts of organic carboxylic acids, for example dibutyltin diacetate, dibutyltin dilaurate, dibutyltin maleate and dioctyltin diacetate; bismuth salts of organic carboxylic acids, such as bismuth octoate; organometallic derivatives of trivalent and pentavalent As, Sb and Bi and metal carbonyls of iron and cobalt; or mixtures thereof. Tertiary amine catalysts comprise organic compounds containing at least one tertiary nitrogen atom and capable of catalyzing the hydroxyl/isocyanate reaction. The tertiary amine, morpholine derivative and piperazine derivative catalysts may comprise, for example, but are not limited to, triethylenediamine, tetramethylethylenediamine, pentamethyldiethylenetriamine, bis (2-dimethylaminoethyl) ether, triethylamine, tripropylamine, tributylamine, tripentylamine, pyridine, quinoline, dimethylpiperazine, piperazine, N-ethylmorpholine, 2-methylpropanediamine, methyltriethylenediamine, 2,4, 6-trimethylamino-methyl) phenol, N', N "-tris (dimethylamino-propyl) s-hexahydrotriazine, or mixtures thereof.

Typically, the catalyst used herein is present in an amount greater than zero and at most 3.0 wt%, preferably at most 2.5 wt%, more preferably at most 2.0 wt%, based on the total weight of component (a).

According to an alternative embodiment of the present disclosure, component (a) is a blend of one or more polyurethane prepolymers with one or more monomeric polyisocyanates, wherein the monomeric polyisocyanates are selected from those used to prepare the polyurethane prepolymers.

Polyol component (a)B)

In various embodiments of the present disclosure, the polyol component (B) comprises one or more second polyols, which may be the same or different from the first polyol used to prepare the polyurethane prepolymer. According to a preferred embodiment of the present application, the second polyol is selected from the group consisting of: c comprising at least two hydroxyl groups₂-C₁₆Aliphatic polyhydroxy alcohols, C containing at least two hydroxyl groups₆-C₁₅Alicyclic or aromatic polyhydric alcohols, C containing at least two hydroxyl groups₇-C₁₅Araliphatic polyhydroxy alcohols, polyester polyols having a molecular weight of from 100 to 5,000 and an average hydroxyl functionality of from 1.5 to 5.0, poly (C) having a molecular weight of from 100 to 5,000₂-C₁₀) Alkylene glycol or poly (C)₂-C₁₀) Polyether polyol of a copolymer of alkylene glycol, polycarbonate diol having a molecular weight of 100 to 5,000, C comprising at least one hydroxyl group and at least one amino group₂-C₁₀Alkanolamines, and combinations thereof. According to one embodiment of the present application, the second polyol is a polymeric polyol (such as one or more of a polyester polyol, a polyether polyol, a polycarbonate diol, and a polyester-polyether copolyol) and a monomeric polyol (such as a C comprising at least two hydroxyl groups)₂-C₁₆Aliphatic polyhydroxy alcohols, C containing at least two hydroxyl groups₆-C₁₅Alicyclic or aromatic polyhydric alcohols, C containing at least two hydroxyl groups₇-C₁₅Araliphatic polyhydroxy alcohols, C containing at least one hydroxyl group and at least one amino group₂-C₁₀One or more of alkanolamines). According to another embodiment of the present application, the second polyol is a blend of a polyester polyol and a polyether polyol.

The reaction between the polyurethane prepolymer component (a) and the polyol component (B) may take place in the presence of one or more catalysts, which may be the same or different from the catalysts used to prepare the polyurethane prepolymer. For example, the catalyst for catalyzing the reaction between component (a) and component (B) may include, for example, glycinates; a tertiary amine; tertiary phosphines such as trialkylphosphines and dialkylbenzylphosphines (dialkylbenzylphosphines); a morpholine derivative; a piperazine derivative; chelates of various metals such As those obtainable from acetylacetone, benzoylacetone, trifluoroacetylacetone, ethyl acetoacetate, etc. with metals such As Be, Mg, Zn, Cd, Pd, Ti, Zr, Sn, As, Bi, Cr, Mo, Mn, Fe, Co and Ni; acidic metal salts of strong acids, such as ferric chloride and stannic chloride; salts of organic acids with various metals such as alkali metals, alkaline earth metals, Al, Sn, Pb, Mn, Co, Ni, and Cu; organotin compounds such as tin (II) salts of organic carboxylic acids, for example tin (II) diacetate, tin (II) dioctoate, tin (II) diethylhexanoate and tin (II) dilaurate, and dialkyltin (IV) salts of organic carboxylic acids, for example dibutyltin diacetate, dibutyltin dilaurate, dibutyltin maleate and dioctyltin diacetate; bismuth salts of organic carboxylic acids, such as bismuth octoate; organometallic derivatives of trivalent and pentavalent As, Sb and Bi and metal carbonyls of iron and cobalt; or mixtures thereof. Tertiary amine catalysts comprise organic compounds containing at least one tertiary nitrogen atom and capable of catalyzing the hydroxyl/isocyanate reaction. Tertiary amines, morpholine derivatives and piperazine derivative catalysts may include, for example, but are not limited to, triethylenediamine, tetramethylethylenediamine, pentamethyldiethylenetriamine, bis (2-dimethylaminoethyl) ether, triethylamine, tripropylamine, tributylamine, tripentylamine, pyridine, quinoline, dimethylpiperazine, piperazine, N-ethylmorpholine, 2-methylpropanediamine, methyltriethylenediamine, 2,4, 6-trimethylamino-methyl) phenol, N', N "-tris (dimethylamino-propyl) s-hexahydrotriazine, or mixtures thereof.

Typically, the catalyst used herein is present in an amount greater than zero and up to 3.0 wt%, preferably up to 2.5 wt%, more preferably up to 2.0 wt%, based on the total weight of the polyurethane composition.

In the present application, the terms "foaming agent" and "foaming agent" are used interchangeably and denote agents that can impart a porous structure to the interior of the resulting PU artificial leather product. The terms "sealed blowing agent", "sealed blowing agent" and "microsphere blowing agent" are used interchangeably and refer to a blowing agent having a core-shell structure.

According to various embodiments of the present disclosure, a sealed blowing agent is present during the reaction between component (a) and component (B) to achieve a mild and smooth foaming process. FIG. 1 is a schematic illustration of an exemplary encapsulated blowing agent. As shown in fig. 1, the sealed blowing agent comprises a core phase sealed within a shell. The shell preferably seals the entire surface of the core phase. According to an alternative embodiment of the present application, the sealed blowing agent comprises a plurality of cores and/or a plurality of shells, wherein the formulation and/or dimensions of each core and/or shell may be the same or different from each other.

According to one embodiment of the present disclosure, the core phase comprises at least one foaming compound (also referred to as foam core compound) selected from the group consisting of: optionally by at least oneC substituted by chlorine and/or fluorine atoms₃-C₁₆Aliphatic hydrocarbon, C optionally substituted by at least one chlorine and/or fluorine atom₆-C₁₆Alicyclic or aromatic hydrocarbons, C optionally substituted by at least one chlorine and/or fluorine atom₂To C₁₆Ether compound, tetrakis (C)₁-C₆Alkyl) silane, tetra (C)₁-C₆Alkoxy) silicon, water, carboxamide compounds, hydrazide, polyamine, nitrile, carboxylate salts, bicarbonate salts, organosulfate salts, carbon dioxide, carbon monoxide, and combinations thereof. According to a preferred embodiment of the present disclosure, the foaming compound within the core phase comprises at least one selected from the group consisting of: propane, butane, pentane, cyclopentane, trichlorofluoromethane, dichlorodifluoromethane, 1, 1-dichlorofluoroethane, dichlorotrifluoroethane, dichloro-difluoroethane, dichlorotetrafluoroethane, trichlorotrifluoro-ethane, 1,1,1,3, 3-pentafluoro-propane, perfluoropropane, water, azodicarbonamide, benzene-sulfonyl hydrazide, dinitroso-pentamethylenetetramine, tosyl hydrazide, azobisisobutyronitrile, barium azodicarboxylate, sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, iron bicarbonate, sodium dodecyl sulfate, nitrogen, carbon dioxide, carbon monoxide, and combinations thereof.

The shell comprises or consists of at least one selected from the group consisting of: acrylic resins, phenolic resins, alkyd resins, polyester resins, amino resins, epoxy resins, copolymers thereof, and blends thereof. According to an embodiment of the present disclosure, the housing comprises a homopolymer or a copolymer formed from at least one monomer selected from the group consisting of: acrylonitrile, methacrylonitrile, α -chloroacrylonitrile, α -ethoxyacrylonitrile, fumaronitrile, methacrylic acid, itaconic acid, maleic acid, fumaric acid, citraconic acid, vinyl chloride, vinylidene chloride, vinyl bromide, vinyl fluoride, vinyl acetate, vinyl propionate, vinyl butyrate, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, n-octyl (meth) acrylate, dodecyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, stearyl (meth) acrylate, 2-chloroethyl (meth) acrylate, phenyl (meth) acrylate, isobornyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, methyl (meth) acrylate, ethyl acrylate, methyl (meth) acrylate, ethyl acrylate, butyl, Beta-carboxyethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, styrene, methylstyrene, ethylstyrene, dimethylstyrene, p-N-butylstyrene, p-tert-butylstyrene, p-N-hexylstyrene, p-N-octylstyrene, p-nonylstyrene, p-N-decylstyrene, p-N-dodecylstyrene, N-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3, 4-dichlorostyrene chlorostyrene, acrylamide, methacrylamide, N-phenylmaleimide, N- (o-chlorophenyl) maleic acid, N-cyclohexylmaleimide, N-laurylmaleimide, ethylene, propylene, butylene, propylene, butylene, or a combination thereof, and a combination thereof, Isobutylene, vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, crotonone, vinyl hexyl ketone, methyl isopropenyl ketone, N-vinyl pyrrole, N-vinyl carbazole, N-vinyl indole, N-vinyl pyrrolidone, allyl methacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, pentaerythritol tetramethacrylate, bis (methacryloyloxymethyl) tricyclodecane, and blends thereof. According to a preferred embodiment of the present disclosure, the shell comprises or consists of an acrylic resin, preferably a rigid acrylic resin.

According to embodiments of the present disclosure, the sealed blowing agent is incorporated in the reaction system between component (a) and component (B) in an "unexpanded" state, and then as the reaction proceeds at a temperature of, for example, 60 ℃ to 300 ℃, preferably 70 ℃ to 250 ℃, more preferably 75 ℃ to 240 ℃, and most preferably 80 ℃ to 235 ℃, it expands under the reaction system to form pores within the resulting polyurethane. For example, the temperature at which the encapsulated blowing agent begins to expand, which is also referred to as "initiation temperature" or "expansion initiation temperature," can be 80 ℃, 82 ℃, 84 ℃, 85 ℃, 88 ℃, 90 ℃, 92 ℃, 94 ℃, 95 ℃, 96 ℃, 98 ℃, 100 ℃, 102 ℃, 104 ℃, 105 ℃, 106 ℃, 108 ℃, 110 ℃, 115 ℃, 118 ℃, 120 ℃, 122 ℃, 125 ℃, 127 ℃, 130 ℃, 132 ℃, 134 ℃, 135 ℃, 137 ℃, 139 ℃, 140 ℃, 142 ℃, 144 ℃, 145 ℃, 147 ℃, 148 ℃, 149 ℃, 150 ℃, or can be within a temperature range obtained by combining any two of the aforementioned values. The maximum temperature during the reaction depends on factors such as the activity/rate of the reaction and the heating/cooling/thermal recycling mechanism, and can be 120 ℃, 125 ℃, 128 ℃, 130 ℃, 132 ℃, 135 ℃, 138 ℃, 140 ℃, 142 ℃, 144 ℃, 145 ℃, 146 ℃, 148 ℃, 150 ℃, 152 ℃, 155 ℃, 158 ℃, 160 ℃, 162 ℃, 165 ℃, 168 ℃, 170 ℃, 172 ℃, 175 ℃, 178 ℃, 180 ℃, 182 ℃, 185 ℃, 188 ℃, 190 ℃, 192 ℃, 195 ℃, 198 ℃, 200 ℃, 202 ℃, 205 ℃, 208 ℃, 210 ℃, 212 ℃, 215 ℃, 218 ℃, 220 ℃, 222 ℃, 225 ℃, 228 ℃, 230 ℃, 232 ℃, 235 ℃, 238 ℃, 240 ℃, 242 ℃, 245 ℃, 248 ℃, 250 ℃, 252 ℃, 255 ℃, 258 ℃, 262 ℃, 265 ℃, 268 ℃, 270 ℃, 275 ℃, 277 ℃, 280 ℃, 282 ℃, 285 ℃, 288 ℃, 290 ℃, 292 ℃, 295 ℃, 298 ℃, 300 ℃, or can be in a temperature range obtained by combining any two of the above values, with the proviso that the maximum temperature is higher than the starting temperature.

According to an embodiment of the present disclosure, the sealed blowing agent has not more than 40kg/m in an unexpanded state³Or not higher than 38kg/m³Or not higher than 35kg/m³Or not higher than 32kg/m³Or not higher than 30kg/m³Or not higher than 28kg/m³Or not higher than 26kg/m³Or not higher than 25kg/m³Or not higher than 23kg/m³Or not higher than 22kg/m³Or not higher than 20kg/m³Or not higher than 18kg/m³Or not higher than 16kg/m³Or not higher than 15kg/m³Or not higher than 12kg/m³Or not higher than 10kg/m³Or not higher than 8kg/m³Or not higher than 7kg/m³Or not higher than 6kg/m³Or not higher than 5kg/m³Low density of (2).

According to an embodiment of the present disclosure, the sealed blowing agent has a particle size in the unexpanded state of 5 μm, or 7 μm, or 8 μm, or 9 μm, or 10 μm, or 12 μm, or 14 μm, or 15 μm, or 17 μm, or 19 μm, or 20 μm, or 22 μm, or 24 μm, or 25 μm, or 27 μm, or 30 μm, or 32 μm, or 34 μm, or 35 μm, or 37 μm, or 39 μm, or 40 μm, or may be within a numerical range obtained by combining any two of the above values. According to an embodiment of the present disclosure, the shell of the sealed blowing agent has a thickness in an unexpanded state of 0.02 μm, or 0.05 μm, or 0.08 μm, or 0.1 μm, or 0.2 μm, or 0.5 μm, or 0.8 μm, or 1 μm, or 2 μm, or 3 μm, or 4 μm, or 5 μm, or 6 μm, or 7 μm, or 8 μm, or 9 μm, or 10 μm, or 11 μm, or 12 μm, or may be within a range of values obtained by combining any two of the above values.

Fig. 1 shows expansion of the sealed blowing agent under heat treatment, wherein the diameter of the sealed blowing agent may be increased to 1.2 times, or 1.5 times, or 1.7 times, or 1.9 times, or 2.0 times, or 2.2 times, or 2.5 times, or 2.8 times, or 3.0 times, or 3.2 times, or 3.5 times, or 3.8 times, or 4.0 times, or 4.2 times, or 4.5 times, or 4.8 times, or 5.0 times, or 5.2 times, or 5.5 times, or 5.8 times, or 6.0 times, or 6.5 times, or 6.8 times, or 7.0 times, or 7.2 times, or 7.5 times, or 7.8 times, or 8.0 times, or 8.2 times, or 8.5 times, or 8.8 times, or 9.0 times, or 9.2 times, or 9.5 times, or 10 times the original diameter of the unexpanded sealed blowing agent. Such expansion may be caused by physical processes (thermal expansion, evaporation, sublimation, etc.), chemical processes (degradation, gas generation, etc.), or a combination thereof. The thickness of the shell will decrease as the expansion proceeds. According to an embodiment of the application, the shell remains intact during the expansion phase, so that no blowing agent leaks out of the core and comes into contact with said component (a) or the second polyol, so that the formation of porosity is mainly dependent on the expansion and the pore structure in the PU product is essentially closed pore.

In alternative embodiments of the present disclosure, a partial shell of the sealed blowing agent, for example, about 5%, 7%, 9%, 10%, 12%, 15%, 17%, 19%, 20%, 22%, 25%, 27%, 29%, 30%, 32%, 35%, 37%, 40%, 42%, 45%, 48%, 50%, 52%, 55%, 58%, 60%, 62%, 65%, 68%, 70%, 72%, 75%, 78%, 80%, 82%, 85%, 88%, 90%, 92%, 95%, 98%, or 100% of the shell of the sealed blowing agent is ruptured during the expansion phase, whereupon the blowing agent leaks out of the shell and contacts the polyurethane prepolymer, second polyol, or any other additive/adjuvant within the system to further create a foam and cellular structure. In such cases, the cellular structure results from a combination of expansion of the core-shell blowing agent and the physical/chemical action of the leaking core blowing agent.

According to embodiments of the present disclosure, the encapsulated blowing agent is present in an amount of 0.1 wt% to 30 wt%, more preferably 0.1 wt% to 10 wt%, more preferably 2 wt% to 7 wt%, more preferably 2.3 wt% to 6.2 wt%, and most preferably 2.5 wt% to 3.5 wt%, based on the total weight of the polyol component (B).

According to an embodiment of the present disclosure, the sealed blowing agent is combined with a second polyol prior to the reaction of component (a) and component (B). According to an alternative embodiment of the present disclosure, the sealed blowing agent, the second polyol and any other ingredients for component (B) are independently blended with component (a), but they are all still considered as ingredients of component (B).

According to a preferred embodiment of the present disclosure, the non-solvent two-component polyurethane artificial leather composition of the present disclosure contains only the enclosed foaming agent and does not contain any other foaming agent. According to various embodiments of the present disclosure, the non-solvent two-component polyurethane artificial leather composition of the present disclosure preferably does not include any foam stabilizer.

Additive agent

In various embodiments of the present disclosure, the non-solvent two-component polyurethane composition comprises one or more additives selected from the group consisting of: chain extenders, crosslinkers, blowing agents other than encapsulated blowing agents, foam stabilizers, tackifiers, plasticizers, rheology modifiers, antioxidants, fillers, colorants, pigments, water scavengers, surfactants, solvents, diluents, flame retardants, anti-slip agents, antistatic agents, preservatives, biocides, antioxidants, and combinations of two or more thereof. These additives can be shipped and stored as separate components and incorporated into the polyurethane composition shortly before or immediately before component (a) and component (B) are combined. Alternatively, when these additives are chemically inert to isocyanate groups or isocyanate-reactive (hydroxyl) groups, they may be contained in one of components (a) and (B).

According to embodiments of the present disclosure, one or more bubble control agents and bubble stabilizers may be included in the non-solvent two-component polyurethane composition.

Chain extenders may be present in the polyurethane foam forming reactants. Chain extenders are chemicals having two isocyanate-reactive groups per molecule and an equivalent weight per isocyanate-reactive group of less than 300, preferably less than 200 and especially from 31 to 125. The isocyanate-reactive group is preferably a hydroxyl group, an aliphatic or aromatic primary amino group or an aliphatic or aromatic secondary amino group. Representative chain extenders include ethylene glycol, diethylene glycol, triethylene glycol, 1, 2-propanediol, dipropylene glycol, tripropylene glycol, 1, 4-butanediol, cyclohexanedimethanol, ethylenediamine, phenylenediamine, bis (3-chloro-4-aminophenyl) methane, dimethylthiotoluenediamine, and diethyltoluenediamine.

One or more crosslinking agents may also be present in the polyurethane foam-forming reactants. For the purposes of the present invention, a "crosslinker" is a material having three or more isocyanate-reactive groups per molecule and an equivalent weight per isocyanate-reactive group of less than 300. Preferably, the crosslinking agent contains 3 to 8, especially 3 to 4 hydroxyl, primary, secondary or tertiary amine groups per molecule and an equivalent weight of 30 to about 200, especially 50 to 125. Examples of suitable crosslinking agents include diethanolamine, monoethanolamine, triethanolamine, mono-, di-, or tri (isopropanol) amine, glycerol, trimethylolpropane, pentaerythritol, and the like.

Chain extenders and crosslinkers are suitably used in small amounts, since hardness increases with increasing amounts of either of these materials. From 0 to 25 parts by weight of a chain extender is suitably used per 100 parts of the combined weight of the first polyol and the second polyol. Preferred amounts are from 1 to 15 parts per 100 parts of the combined weight of the first polyol and the second polyol. The crosslinking agent is suitably used in an amount of 0 to 10 parts by weight per 100 parts of the combined weight of the first polyol and the second polyol. Preferred amounts are from 0 to 5 parts per 100 parts of the combined weight of the first polyol and the second polyol.

Fillers may be present in the polyurethane composition. Fillers are included primarily to reduce cost. Particulate rubber materials are particularly useful fillers. Such fillers may comprise 1 to 50% or more by weight of the polyurethane composition.

Additional blowing agents other than encapsulated blowing agents include water, air, nitrogen, argon, carbon dioxide and C₄-C₈Hydrocarbons, C₄-C₈Hydrofluorocarbons and C₄-C₈Chlorofluorocarbons, all of which are not sealed in any shell. Surfactants may be present in the reaction mixture. Surfactants may also be used to wet the filler particles and thereby aid in dispersing the filler particles into the reactive composition and the elastomer. Silicone surfactants are widely used for this purpose and may also be used here. The amount of surfactant used is typically between 0.02 and 1 part by weight per 100 parts of the combined weight of the first and second polyols.

According to a preferred embodiment of the present disclosure, the polyurethane composition is substantially free of water or moisture intentionally added thereto. For example, "free of water" or "anhydrous" means that the mixture of all raw materials comprises less than 3 weight percent, preferably less than 2 weight percent, preferably less than 1 weight percent, more preferably less than 0.5 weight percent, more preferably less than 0.2 weight percent, more preferably less than 0.1 weight percent, more preferably less than 100ppm by weight, more preferably less than 50ppm by weight, more preferably less than 10ppm by weight, more preferably less than 1ppm by weight of water, based on the total weight of the mixture of raw materials used to prepare the polyurethane composition.

According to a preferred embodiment of the present disclosure, the polyurethane composition is substantially free of any organic solvent intentionally added thereto. For example, "free of organic solvent" or "organic solvent free" means that the mixture of all raw materials used to prepare the polyurethane composition comprises less than 3 weight percent, preferably less than 2 weight percent, preferably less than 1 weight percent, more preferably less than 0.5 weight percent, more preferably less than 0.2 weight percent, more preferably less than 0.1 weight percent, more preferably less than 100 weight ppm, more preferably less than 50 weight ppm, more preferably less than 10 weight ppm, more preferably less than 1 weight ppm of organic solvent based on the total weight of the raw material mixture.

According to a preferred embodiment of the present disclosure, the polyurethane composition is substantially free of any solvents intentionally added thereto. As disclosed herein, the term "solvent" refers to organic and inorganic liquids whose function is to dissolve only one or more solid, liquid or gaseous materials without initiating any chemical reaction. In other words, although some organic compounds, such as ethylene glycol and propylene glycol and water, which are generally considered "solvents" in polymerization technology, are used for preparing PU foams, none of them belong to "solvents" because they mainly act as isocyanate-reactive functional substances, chain extenders or blowing agents, etc., by initiating chemical reactions.

Release layer

Release films are also known as release layers, or in the art are commonly referred to as "release papers". Examples of suitable release films/layers include foils of metal, plastic or paper. In a preferred embodiment of the present disclosure, the release layer is a paper layer, optionally coated with a plastic film. Preferably, the paper layer disclosed herein is coated with a polyolefin, more preferably with polypropylene. Alternatively, the paper layer is preferably coated with silicone. In an alternative embodiment, the release layer used herein is a PET layer, optionally coated with a plastic film. Preferably, the PET layer may be coated with a polyolefin, more preferably with polypropylene. Alternatively, the PET layer is preferably coated with silicone. Examples of suitable release layers are commercially available. The release layer used in the present disclosure may have a flat, embossed or patterned surface so that a corresponding or complementary surface profile may be formed on the outermost surface of the artificial leather article. Preferably, the release layer is textured in a leather-textured manner to impart good tactile properties to the artificial leather article comparable to high-grade natural leather. The thickness of the release layer is typically 0.001mm to 10mm, preferably 0.01mm to 5mm and more preferably 0.1mm to 2 mm.

The material and thickness of the release layer may be appropriately adjusted as long as the release layer can endure chemical reaction, mechanical processing and heat treatment experienced during the manufacturing process and can be easily peeled from the resulting artificial leather without causing delamination between the top skin film and the 2K PU foam base layer.

Support layer

In embodiments of the present disclosure, the carrier layer is also referred to as a backing substrate and has a thickness in the range of 0.01mm to 50mm, preferably in the range of 0.05mm to 10mm, and more particularly in the range of 0.1mm to 5 mm. The carrier layer may comprise one or more selected from the group consisting of: a fabric, preferably a woven or non-woven fabric, a dipped fabric, a knitted fabric, a braided fabric or a microfiber; metal or plastic foils, such as rubber, PVC or polyamide; and leather, preferably split leather.

The support layer may be made of a woven or non-woven textile. Preferably, the textile is a non-woven textile. The textile may be manufactured by any suitable method, such as those known in the art. The textile may be made from any suitable fibrous material. Suitable fibrous materials include, but are not limited to, synthetic fibrous materials and natural fibrous materials or semi-synthetic fibrous materials and mixtures or blends thereof. Examples of synthetic fiber materials include polyesters, polyamides, acrylics, polyolefins, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, and blends or mixtures thereof. Examples of natural semi-synthetic fibrous materials include cotton, wool, and hemp.

Manufacturing technique

According to embodiments of the present disclosure, a synthetic polyurethane leather product may be prepared by a method using a composition of the present disclosure, wherein the method comprises the steps of i) reacting a polyisocyanate compound with a first polyol to form (a) a polyurethane prepolymer component comprising one or more polyurethane prepolymers; ii) mixing (a) a polyurethane prepolymer component with (B) a polyol component to form a precursor mixture; iii) applying the precursor mixture to one surface of a release film to form a green layer; iv) optionally applying a carrier layer to a surface of the green layer opposite the release film; iv) heating the green layer to form a foamed polyurethane leather layer; and v) optionally, peeling the foamed polyurethane leather layer from the release film.

The product thus produced comprises a foamed polyurethane leather layer, an optional release film and an optional carrier layer. The composition formed by combining component (a) and component (B) may be applied by conventional coating techniques such as spraying, knife coating, die coating, cast coating, and the like.

In embodiments of the present disclosure, the type and molar content of the polyisocyanate in component (a), the first polyol and the second polyol in component (a) are particularly selected such that the total equivalent ratio of NCO groups to hydroxyl groups is in the range of from 0.9:1 to 1.8:1, preferably in the range of from 0.92:1 to 1.6:1, preferably in the range of from 0.95:1 to 1.5:1, and more preferably in the range of from 1:1 to 1.45:1, more preferably in the range of from 1.05:1 to 1.4:1, and more preferably in the range of from 1.10:1 to 1.35: 1.

The coating may be partially or fully cured before the next layer, e.g. the carrier layer, is applied.

According to one embodiment, component (a) and component (B) are mixed together, applied onto a release film, and pre-cured by heating in an oven at a temperature of, for example, 70 ℃ to 130 ℃, preferably 75 ℃ to 100 ℃, for a short duration of 10 seconds to 5 minutes, preferably 30 seconds to 2 minutes, more preferably 45 seconds to 90 seconds. A carrier layer (e.g. a textile fabric) is then applied to the pre-cured 2K PU foam layer with the aid of a press roll, followed by post-curing at a higher temperature of e.g. 105 ℃ to 150 ℃, preferably 110 ℃ to 140 ℃, for a longer duration of 2 minutes to 20 minutes, preferably 3 minutes to 10 minutes, more preferably 4 minutes to 10 minutes. The two-stage curing process described above is intended to ensure a high adhesive strength between the precured 2K PU foam and the carrier layer. According to one embodiment, the resulting 2K foamed PU layer has a thickness of 0.01 to 1000 μm, preferably 10 to 500 μm, and more preferably 200 to 500 μm.

According to a preferred embodiment of the present disclosure, the release film/layer is removed after the 2K PU foam has been fully cured. The release layer may be peeled off via any common technique.

According to a preferred embodiment of the present disclosure, after removing the release layer, a top finishing layer may be applied onto the surface of the artificial leather (i.e., on the outermost surface of the top coating layer) and dried to form a protective film layer. The presence of the finishing layer may further increase the abrasion resistance of the multi-layer artificial leather. The protective film layer can be formed by using any suitable raw materials and techniques. The finishing layer may optionally include additives such as wetting agents, cross-linking agents, binders, matting agents, hand modifiers, pigments and/or colorants, thickeners, or other additives for the top coat. The artificial leathers disclosed herein may further comprise one or more optional additional layers, such as a color layer between the skin layer and the finish layer. Other suitable optional additional layers may be selected from the group consisting of a water repellent layer, a UV protective layer, and a tactile (touch/feel) modifying layer.

The process of the present invention may be carried out continuously or batchwise. An example of a continuous process is a roll-to-roll process and is schematically illustrated in fig. 2. A roll of release film/release layer is unwound and conveyed through two or more stations, where a mixture for a 2K non-solvent PU foam is applied. Heating or irradiation means may be arranged after each coating station to promote drying or curing of the coating layer, and rollers may also be used to enhance the bond strength between layers. The length of the unwound release layer is typically from 10 to 20,000 meters, from 10 to 15,000 meters and preferably from 20 to 10,000 meters, and is typically conveyed at a speed in the range of from 0.1 to 60 meters per minute, preferably from 3 to 45 meters per minute, more preferably from 5 to 15 meters per minute. At the end of the continuous technique, the release layer is peeled off and wound on a mandrel. The rolled release layer may be reused, preferably at least 2 times.

The carrier layer/backing substrate/leather base may be provided in a roll-to-roll manner, i.e. the carrier layer is provided as a roll, unrolled and applied onto the surface of the partially cured 2K non-solvent PU foam, then the 2K non-solvent PU foam is fully cured, and the laminated artificial leather article may be wound on a spindle and stored/sold as a roll.

In a preferred embodiment, the artificial leather is oriented by stretching in one or two directions (i.e., uniaxial or biaxial orientation). The size of the oriented artificial leather may be increased by 1.1 to 5 times, preferably 1.2 to 2 times. The oriented artificial leather exhibits improved breathability.

The multi-layered artificial leather disclosed herein may be cut or otherwise shaped to have a shape suitable for any desired purpose, such as shoe manufacturing. Depending on the intended application, the artificial leather may be further treated or post-treated like natural leather, for example by brushing, filling, grinding or ironing. If desired, artificial leathers (e.g., natural leathers) can be finished with conventional finishing compositions. This provides further possibilities to control its properties. The multilayer structures disclosed herein can be used in a variety of applications that are particularly suited for use as artificial leathers, such as footwear, handbags, belts, purses, clothing, upholstery, automotive upholstery, and gloves. The multilayer structure is particularly suitable for automotive applications.

Examples of the invention

Some embodiments of the invention will now be described in the following examples. However, the scope of the present disclosure is of course not limited to the formulations described in these examples. Rather, the examples are merely illustrative of the present disclosure.

The information of the raw materials used in the examples is listed in table 1 below:

TABLE 1 raw materials used in the examples

Preparation examples 1 to 4 and control examples: synthesis of non-solvent two-component polyurethane compositions

In the preparation examples and the control examples, VORANOL was added^TM CP 6001、VORANOL^TM 4240、SPECFLEX^TMNC 701, FOMREZ UL-29 and Expancel 031 DU40/Expancel 043 DU80 were mixed with a FlackTek high speed mixer (model #: DAC150.1 FVA) at 2500rpm for 2.5 minutes. The mixer can mix samples without mixingAny bubbles are generated therein. SPECFLEX is then added^TMNE 1156 was added to the reaction system and mixed with a FlackTek high speed mixer at 2500rpm for 0.5 minutes to produce a PU-prepolymer/polyol mixture.

In these examples, a continuous coating apparatus as shown in fig. 2 was used, in which the above-described PU-prepolymer/polyol mixture was applied to a release paper by means of a knife with a gap controller. The coated release paper was pre-cured in an oven at 90 ℃ for 40 seconds. The fabric was optionally applied to the surface of the PU resin layer opposite the release paper with the aid of a 3.9Kg roll. The laminate thus formed was fully cured in an oven at 140 ℃ for 4 minutes. The cured product was cooled to ambient temperature, after which the release paper was peeled off, and the final product was cut into standard samples for testing.

TABLE 2 formulation of inventive examples 1 to 4 and comparative examples

Technique for characterizing PU films

Tensile strength of PU film

Pure PU films were prepared according to the above procedure without application of fabric. The resulting PU films were cut into micro "dog" bone samples according to ASTM D638-10. The upper and lower ends of each sample were fixed on an Instron machine and their tensile strength was characterized at a speed of 50 cm/min. The resin film characteristics are shown in Table 3.

Peel strength of leather

The three-layer laminate comprising release paper, PU layer and latex was cut into leather samples having a size of 20cm × 3cm, and the samples were coated on the skin surface thereof with epoxy glue. Each sample was then folded with the epoxy coated surface facing each of the samples to form 10cm x 3cm samples. The folded sample was pressed and cured overnight at room temperature. The test for T-peel strength, elongation and modulus @ 100% was then performed on an Instron. And a force applying device for recording the peeling force for peeling the two surfaces. Three specimens were tested for each sample and the resulting peel forces were recorded and summarized in table 4. Normal requirements for peel strength in the industry are >20N, medium end >40N, and high end > 80N.

Fabric of leather is inflected (balloon Flex)

The synthetic leather was cut into two 7.5cm by 4.5cm pieces per direction. Two samples in different directions were fixed on two fabric deflection test machines (one for testing fabric deflection at room temperature, the other for testing fabric deflection at-15 ℃ and two samples in two directions were required for each temperature test). The two pairs of fabrics were tested for flex at a rate of 100 times/min. The Room Temperature (RT) fabric deflection test required 100000 times, and the-15 ℃ fabric deflection test required 30000 times. The fabric deflection characterization data are listed in table 5. The low end requirement is 50000 times at RT and the high end requirement is 100000 times at RT and 30000 times at-15 ℃.

Leather SEM image

Scanning Electron Microscope (SEM) photographs of the cross-section and surface of the PU foam layer were taken at an accelerated electron voltage of 5.00 KV. The cross section was exposed by cutting the test piece with a knife, and fig. 3a to 3e show Scanning Electron Microscopes (SEM) of the cross section and surface of PU foam manufactured in inventive examples, comparative examples and comparative examples of the present disclosure.

Table 3: tensile Strength Properties

	Control	Inventive example 1	Inventive example 2	Inventive example 4
					Tensile strength/MPa	8.41	1.99	1.29	0.53
Elongation/percent	638	420	323	145
					Modulus @ 100%/MPa	1.61	0.82	0.84	0.47

Table 4: fabric folding performance

	Control	Inventive example 1	Inventive example 2	Inventive example 3	Inventive example 4
						Axial (RT)/times	>100000	>100000	>100000	>100000	>100000
Transverse direction (RT)/times	>100000	>100000	>100000	>100000	>100000
						Axial direction (-15 deg.C)/time	>30000	>30000	>30000	>30000	>30000
Transverse direction (-15 deg.C)/times	>30000	>30000	>30000	>30000	>30000

Table 5: peel strength properties

	Control	Inventive example 1	Inventive example 2	Example 3	Inventive example 4
						Peel strength N/(3cm)	20	42	62	29	44

Conclusion

According to the microscopic morphology shown in fig. 3a to 3e, the encapsulated blowing agent can produce uniform bubbles with good hand in the PU resin without using any stabilizer. The mechanical properties of the foamed PU resins meet the general requirements for foamed materials. As can be seen from table 4, the unfoamed and foamed samples showed comparable fabric flex results, and all samples passed the highest fabric flex requirements in the leather industry. The unfoamed PU leather did not exhibit high peel strength, probably due to the faster reaction rate prior to applying the fabric to the 2K PU foam layer. In addition, the foamed PU samples with low amounts of blowing agent can achieve better performance characteristics than those containing higher amounts of blowing agent.

Claims

1. A non-solvent two-component polyurethane artificial leather composition comprising:

(A) a polyurethane prepolymer component comprising one or more polyurethane prepolymers prepared by reacting at least one polyisocyanate compound with at least one first polyol, wherein the polyurethane prepolymers comprise at least two free isocyanate groups; and

(B) a polyol component comprising at least one second polyol;

wherein the polyol component further comprises an encapsulated blowing agent comprising at least one foam core phase encapsulated within the shell.

2. The composition of claim 1, wherein the foam core phase comprises at least one selected from the group consisting of: c optionally substituted by at least one chlorine and/or fluorine atom₃-C₁₆Aliphatic hydrocarbon, C optionally substituted by at least one chlorine and/or fluorine atom₆-C₁₆Alicyclic or aromatic hydrocarbons, C optionally substituted by at least one chlorine and/or fluorine atom₂To C₁₆Ether compound, tetrakis (C)₁-C₆Alkyl) silane, tetra (C)₁-C₆Alkoxy) silicon, water, carboxamide compounds, hydrazide, polyamine, nitrile, carboxylate salts, bicarbonate salts, organosulfate salts, carbon dioxide, carbon monoxide, and combinations thereof; and is

The housing comprises at least one selected from the group consisting of: acrylic resins, phenolic resins, alkyd resins, polyester resins, amino resins, epoxy resins, copolymers thereof, and blends thereof.

3. The composition of claim 2, wherein the foam core phase comprises at least one selected from the group consisting of: propane, butane, pentane, cyclopentane, trichlorofluoromethane, dichlorodifluoromethane, 1, 1-dichlorofluoroethane, dichlorotrifluoroethane, dichlorodifluoroethane, dichlorotetrafluoroethane, trichlorotrifluoro-ethane, 1,1,1,3, 3-pentafluoropropane, perfluoropropane, water, azodicarbonamide, benzene-sulfonyl hydrazide, N' -dinitrosopentamethylenetetramine, toluenesulfonyl hydrazide, azobisisobutyronitrile, barium azodicarboxylate, sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, iron bicarbonate, sodium dodecyl sulfate, nitrogen, carbon dioxide, carbon monoxide, and combinations thereof; and/or

The shell comprises a homopolymer or copolymer formed from at least one monomer selected from the group consisting of: acrylonitrile, methacrylonitrile, α -chloroacrylonitrile, α -ethoxyacrylonitrile, fumaronitrile, methacrylic acid, itaconic acid, maleic acid, fumaric acid, citraconic acid, vinyl chloride, vinylidene chloride, vinyl bromide, vinyl fluoride, vinyl acetate, vinyl propionate, vinyl butyrate, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, n-octyl (meth) acrylate, dodecyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, stearyl (meth) acrylate, 2-chloroethyl (meth) acrylate, phenyl (meth) acrylate, isobornyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, methyl (meth) acrylate, ethyl acrylate, methyl (meth) acrylate, ethyl acrylate, butyl, Beta-carboxyethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, styrene, methylstyrene, ethylstyrene, dimethylstyrene, p-N-butylstyrene, p-tert-butylstyrene, p-N-hexylstyrene, p-N-octylstyrene, p-nonylstyrene, p-N-decylstyrene, p-N-dodecylstyrene, N-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3, 4-dichlorostyrene chlorostyrene, acrylamide, methacrylamide, N-phenylmaleimide, N- (o-chlorophenyl) maleic acid, N-cyclohexylmaleimide, N-laurylmaleimide, ethylene, propylene, butylene, propylene, butylene, or a combination thereof, and a combination thereof, Isobutylene, vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, crotonone, vinyl hexyl ketone, methyl isopropenyl ketone, N-vinyl pyrrole, N-vinyl carbazole, N-vinyl indole, N-vinyl pyrrolidone, allyl methacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, pentaerythritol tetramethacrylate, bis (methacryloyloxymethyl) tricyclodecane, and blends thereof.

4. The composition of claim 1 wherein the encapsulated blowing agent is present in an amount of 2 to 7 weight percent based on the total weight of the polyol component (B).

5. The composition of claim 1 wherein the encapsulated blowing agent is present in an amount of from 2.5 to 3.5 weight percent based on the total weight of the polyol component (B).

6. The composition of claim 1, wherein the sealed blowing agent has at least one of the following parameters:

a) having a particle size of 5 to 40 μm;

b) having a shell thickness of 0.1 to 10 μm;

c) the particle size can expand 2 to 10 times irreversibly or reversibly when heated;

d) having a density of 30kg/cm³Or a lower pre-expansion density;

e) has an expansion onset temperature of 80 ℃ to 150 ℃; and

f) has a softening temperature of 120 ℃ to 235 ℃.

7. The composition of claim 1, wherein the sealed blowing agent has a particle size of 16 to 24 μ ι η, an expansion onset temperature of 95 to 115 ℃, 10kg/cm³Or a pre-expanded density of less, a softening temperature of 147 ℃ to 167 ℃; and is

Wherein the outer shell is formed of an acrylic resin and the foam core phase is C optionally substituted with at least one chlorine atom and/or fluorine atom₃-C₁₆An aliphatic hydrocarbon.

8. The composition of claim 1, wherein the polyisocyanate compound is selected from the group consisting of: containing at least two isocyanidesC of an ester group₄-C₁₂Aliphatic polyisocyanate, C containing at least two isocyanate groups₆-C₁₅Alicyclic or aromatic polyisocyanates, C containing at least two isocyanate groups₇-C₁₅An araliphatic polyisocyanate, and any combination thereof; and is

Each of the first polyol and the second polyol is independently selected from the group consisting of: c comprising at least two hydroxyl groups₂-C₁₆Aliphatic polyhydroxy alcohols, C containing at least two hydroxyl groups₆-C₁₅Alicyclic or aromatic polyhydric alcohols, C containing at least two hydroxyl groups₇-C₁₅Araliphatic polyhydroxy alcohols, polyester polyols having a molecular weight of from 100 to 5,000 and an average hydroxyl functionality of from 1.5 to 5.0, poly (C) having a molecular weight of from 100 to 5,000₂-C₁₀) Alkylene glycol or poly (C)₂-C₁₀) Polyether polyol of a copolymer of alkylene glycol, polycarbonate diol having a molecular weight of 100 to 5,000, C comprising at least one hydroxyl group and at least one amino group₂-C₁₀Alkanolamines, and combinations thereof.

9. The composition of claim 1, wherein the weight ratio between the polyurethane prepolymer component (a) and the polyol component is from 100:40 to 100: 60.

10. The composition of claim 1, wherein the polyurethane prepolymer has an NCO content of 10 to 20 wt% and a viscosity of 50 to 10,000 cSt.

11. The composition of claim 1, wherein the second polyol comprises a polyether polyol modified with a comonomer of styrene and acrylonitrile, having a molecular weight of 2,000 to 3,000, an average OH number of 20 to 25mg KOH/g, a viscosity of 4500 to 4900cSt, and a solids content of 25 to 45 wt%.

12. The composition of claim 1, wherein the composition comprises no more than 2 wt% aqueous solvent and no more than 2 wt% organic solvent; or

The composition is free of aqueous solvents and free of organic solvents.

13. The composition of claim 1, wherein the composition does not comprise any blowing agent other than the encapsulated blowing agent; and/or

The composition does not contain a foam stabilizer.

14. A method of preparing an artificial polyurethane leather product by using the composition of any one of claims 1 to 13, comprising:

i) reacting a polyisocyanate compound with a first polyol to form (a) a polyurethane prepolymer component comprising one or more polyurethane prepolymers;

ii) mixing the (a) polyurethane prepolymer component with (B) a polyol component to form a precursor mixture;

iii) applying the precursor mixture onto one surface of a release film to form a green layer;

iv) optionally applying a carrier layer onto the surface of the green layer opposite the release film;

iv) heating the green layer to form a foamed polyurethane leather layer; and

v) optionally, peeling the foamed polyurethane leather layer from the release film.

15. An artificial polyurethane leather product made by the process of claim 14, wherein the product comprises a foamed polyurethane leather layer, an optional release film, and an optional carrier layer.